But the former Rangers ace last night warned his mate he could face trouble if he tries to change too much too soon.

Berg was delighted to see fellow Norwegian land the job in the city where he served at Ibrox.

As part of the pioneering band of coaches fleeing the fjords it’s a massive shot in the arm for Norway’s game.

Berg savoured success in Poland a couple of weeks ago when he won the championship with Legia Warsaw and Deila now has a plum job of his own.

Given the coaches share information to help each other, Berg is well aware of how his pal wants to shape Celtic up – but he has issued a caveat to Deila that subtle changes may be the way.

Berg said: “I have no worries on the football front for Ronny. The only thing he will have to find out is how quickly can he change to how he wants to play compared with Celtic now.

“I know how Ronny wants to play and I know how Celtic do play right now. It’s different, can I say. He has to make sure he doesn’t make too many changes too early.”

But Berg insists Deila is way too smart to mess up. And he backs him to be a major success in Glasgow when he quickly comes to terms with suffocating life in Glasgow.

Berg said: “Ronny knows what it is about in different countries, even though this is his first taste outside of Norway. He is a smart guy.

“He’ll know how the people feel – he’s a passionate guy himself. The fans at Celtic are enthusiastic and he will be the same. If the fans are passionate he will be too.

“Ronny is a very good coach. After he stopped playing he was assistant for a few years then coach.

“His teams play attractive and offensive football. He’s won the league with a smaller team based on good football and being good at home.

“Celtic is a very good move for him and Celtic. He’ll play the way Celtic expect, in terms of dominating matches and being favourites for most matches. His intelligence will see him through and maybe into Europe too.”

Deila’s move has made major waves in his homeland and Berg reckons it’s another big boost.

Although exported players have been a big triumph for the country their managers so far have failed abroad.

But Berg is blazing a trail with success in Poland and believes Deila and more gaffers will do the same.

He said: “What Ronny did at Stromsgodset was a bit like Aberdeen defeating Celtic and Rangers to win the Scottish title. Stromsgodset were able to find players on the cheap but were also able to get good players on good wages in the past couple of years.

“Compared with Molde, Rosenborg, Viking Stavanger or Brann Bergen they are nowhere near in terms of money.

“What they did well is produce players and develop talented ones as well as signing some experience with paying no transfer fees.

“It’s good for Norwegian football if more coaches work abroad and do well. Coaches have gone to big leagues before and perhaps not been so successful.

“But if you go straight from Norway to the likes of the Premiership, La Liga or Bundesliga it’s very tough because you won’t get the top jobs.

“Ole-Gunnar Solskjaer, for example, got a job at Cardiff where, with the greatest respect, they are not going to win the Premier League.

“But there is a good culture in terms of how we share knowledge, how you work on a daily basis and the coaches now have a better chance to do well in the bigger clubs outside Norway.

“I remember Scotland were able to produce fantastic managers for a number of years.

“I’m not saying Norway will do exactly that but there are opportunities for Norwegians to go abroad and football is getting more international.

“Norwegian coaches have the right mentality, the right values and the right confidence.

“The best Norwegian coach ever was Nils-Arne Eggen. He took Rosenborg to the Champions League constantly and won the title 13 years in a row.

“Mr Eggen used to invite all of the coaches and say, ‘Everyone can watch our training, everyone can copy what they want, if anyone has any questions, I’ll answer them’.

“Then he added, ‘But you are just copies. There is only one original. Me! You can copy and be good like me but you won’t be that good’.

“He had the confidence and he really helped Norwegian football. When Norway had success in the 1990s the co-operation between the coaches was very good and Egil Olsen was also keen to talk to others and learn.

“Sharing information is part of Norwegian culture. We are a small country and we can’t sit in our own little camps. That’s no good for anyone.

“Celtic have fantastic traditions and there have been top managers. If he does well there he might stay a long time or go to a bigger job. To start at Celtic is perfect for him and the club.”